Isopropyl palmitate is an ester formed by the reaction between isopropyl alcohol (C₃H₈O) and palmitic acid (C₁₆H₃₂O₂). The chemical structure consists of a hydrophilic (water-attracting) isopropyl group and a hydrophobic (water-repelling) fatty acid chain. This combination of properties allows it to act as a bridging agent between oil and water-based components in cosmetic formulations, enhancing both product stability and skin penetration.

Physical Properties
Isopropyl palmitate is a colorless to pale yellow, odorless liquid at room temperature. It is highly soluble in oils and other organic solvents but insoluble in water. It has a low viscosity, making it easy to spread on the skin and contributing to its lightweight, non-greasy feel. The ester has a melting point of around 13-14°C and a boiling point of approximately 282°C. Its emollient properties help reduce the greasy or heavy feel of oily products, making formulations more pleasant to use.

Production Process
Isopropyl palmitate is produced through the following steps:

1. Esterification: Palmitic acid, typically derived from palm oil, reacts with isopropyl alcohol under controlled conditions to form the ester compound. This process involves the removal of a water molecule as the two components combine.

2. Purification: The resulting product is refined and purified to ensure the removal of any residual reactants or byproducts, producing a high-quality ester suitable for use in cosmetic and pharmaceutical formulations.

3. Quality Control and Packaging: The purified isopropyl palmitate is subjected to quality control tests to confirm its purity and performance characteristics before being packaged for use in product formulations.

Applications

• Cosmetics: Isopropyl palmitate is widely used as an emollient in lotions, creams, and other personal care products. It enhances the spreadability of products, making them feel smooth and silky on the skin. It also acts as a solvent for active ingredients and helps improve the absorption of moisturizing and anti-aging compounds. Additionally, it is used as a thickener to give products a more luxurious texture without making them feel heavy or greasy.

• Hair Care: In hair care formulations, isopropyl palmitate helps condition and soften the hair while improving the spreadability and texture of products such as conditioners, styling creams, and serums.

• Makeup: Isopropyl palmitate is often used in makeup products such as foundations, blushes, and lipsticks to improve their spreadability and ensure even application. It prevents the formulation from feeling too heavy on the skin, providing a lightweight finish.

INCI Functios:

Skin conditioning agent - Emollient. Emollients have the characteristic of enhancing the skin barrier through a source of exogenous lipids that adhere to the skin, improving barrier properties by filling gaps in intercorneocyte clusters to improve hydration while protecting against inflammation. In practice, they have the ability to create a barrier that prevents transepidermal water loss.  Emollients are described as degreasing or refreshing additives that improve the lipid content of the upper layers of the skin by preventing degreasing and drying of the skin. The problem with emollients is that many have a strong lipophilic character and are identified as occlusive ingredients; they are oily and fatty materials that remain on the skin surface and reduce transepidermal water loss. In cosmetics, emollients and moisturisers are often considered synonymous with humectants and occlusives.

Binder. A binding compound that is used in cosmetic, food and pharmaceutical products as an anti-caking agent with the function of making the product in which it is incorporated silky, compact and homogenous. The binder, either natural such as mucilage, gums and starches or chemical, may be in the form of a powder or liquid.

Fragrance. It plays a very important role in the formulation of cosmetic products as it allows perfume to be enhanced, masked or added to the final product, improving its commercial viability.  The consumer always expects to find a pleasant scent in a cosmetic product.

• Pharmaceuticals: In topical medications, isopropyl palmitate serves as a vehicle to enhance the absorption of active ingredients through the skin, improving the effectiveness of treatments such as creams and ointments.

Environmental and Safety Considerations
Isopropyl palmitate is generally considered safe for use in cosmetics and personal care products. It is non-toxic, non-irritating, and non-sensitizing when applied to the skin. However, in rare cases, it may cause mild irritation or allergic reactions in individuals with very sensitive skin, so it should be used in accordance with recommended guidelines. It is important to source isopropyl palmitate responsibly, as it is often derived from palm oil, a resource that can contribute to deforestation and habitat destruction if not sustainably sourced.

Environmentally, isopropyl palmitate is not biodegradable, and when used in wash-off products, it may contribute to water pollution if not managed properly. Therefore, formulations that use isopropyl palmitate should aim to minimize its environmental impact by using sustainable palm oil sources certified by organizations like the Roundtable on Sustainable Palm Oil (RSPO).

Isopropyl Palmitate studies

Molecular Formula: C₁₉H₃₈O₂

Linear Formula CH₃(CH₂)₁₄COOCH(CH₃)₂ 

Molecular Weight: 298.511 g/mol

UNII: 8CRQ2TH63M

CAS: 142-91-6

EC Number: 205-571-1

PubChem Substance ID 329750203

MDL number MFCD00008993

Beilstein Registry Number 1786567

Synonyms:

• Isopropyl hexadecanoate
• Isopalm
• Deltyl
• Isopal
• Propal
• Deltyl prime
• Tegester isopalm
• propan-2-yl hexadecanoate
• Tegosoft P
• Liponate IPP
• 2-propyl hexadecanoate
• Ja-fa ippkessco
• Sinnoester PIT
• Hexadecanoic acid, 1-methylethyl ester
• Crodamol IPP
• Plymouth IPP
• Starfol IPP
• Unimate IPP
• Kessco IPP
• Emcol-IP
• Isopropyl n-hexadecanoate
• Wickenol 111
• Stepan D-70
• Emerest 2316
• Nikkol IPP
• Estol 103
• Usaf ke-5
• 1-Methylethyl hexadecanoate
• JA-FA Ipp
• Palmitic acid, isopropyl ester
• Kessco isopropyl palmitate
• Hexadecanoic acid, isopropyl ester

References__________________________________________________________________________

Luís Â, Gallardo E, Ramos A, Domingues F. Design and Characterization of Bioactive Bilayer Films: Release Kinetics of Isopropyl Palmitate. Antibiotics (Basel). 2020 Jul 24;9(8):443. doi: 10.3390/antibiotics9080443.

 Abstract. Active packaging incorporating antioxidants and antimicrobials is creating a niche in the market and becoming increasingly important. The main goal of this work was the design of bioactive bilayer films (zein/pullulan) incorporating licorice essential oil. The bilayer films were fully characterized in terms of their chemical, physical, barrier, antioxidant, and antimicrobial properties. Furthermore, the release kinetics of isopropyl palmitate, the major compound of the licorice essential oil, was evaluated by HPLC-DAD (high-performance liquid chromatography coupled to diode-array detector). Scanning Electron Microscopy (SEM) micrographs of cross-sections of the bilayer films clearly show the two layers of the films. Besides presenting the capacity to scavenge free radicals and to inhibit the lipid peroxidation, the developed bilayer films were also able to inhibit the growth of known foodborne pathogens (Enterococcus faecalis and Listeria monocytogenes). The release kinetics profile of isopropyl palmitate from bilayer films incorporating licorice essential oil demonstrated that in 50% ethanol at room temperature, the release was more effective, suggesting that the bilayer films will be more efficient if applied to package semi-fatty food.

Guo H, Liu Z, Li J, Nie S, Pan W. Effects of isopropyl palmitate on the skin permeation of drugs. Biol Pharm Bull. 2006 Nov;29(11):2324-6. doi: 10.1248/bpb.29.2324. 

Abstract. The model penetrants oxaprozin, nimesulide, gliclazide, and ribavirin, because of their different lipophilicities, were selected to assess the enhancing activity of pre-treatment solutions consisting of isopropyl palmitate (IP) in ethanol (5%, 10%, 15%and 20%, w/w, respectively) across excised rat skin using Franz diffusion cells and HPLC detection. All pre-treatment solutions produced a significant increase in the flux and permeation of all four penetrants (p<0.001) and a relationship between penetrant lipophilicity and enhancement effect was observed. The general order of IP effectiveness at concentration was 20%>15%>10%>5% (w/w). The lag-time of drugs did not significantly change except for ribavirin.

Boonme P, Krauel K, Graf A, Rades T, Junyaprasert VB. Characterization of microemulsion structures in the pseudoternary phase diagram of isopropyl palmitate/water/Brij 97:1-butanol. AAPS PharmSciTech. 2006 May 12;7(2):E45. doi: 10.1208/pt070245. 

Abstract. This research was aimed to characterize microemulsion systems of isopropyl palmitate (IPP), water, and 2:1 Brij 97 and 1-butanol by different experimental techniques. A pseudoternary phase diagram was constructed using water titration method. At 45% wt/wt surfactant system, microemulsions containing various ratios of water and IPP were prepared and identified by electrical conductivity, viscosity, differential scanning calorimetry (DSC), cryo-field emission scanning electron microscopy (cryo-FESEM) and nuclear magnetic resonance (NMR). The results from conductivity and viscosity suggested a percolation transition from water-in-oil (water/oil) to oil-in-water (oil/water) microemulsions at 30% wt/wt water. From DSC results, the exothermic peak of water and the endothermic peak of IPP indicated that the transition of water/oil to oil/water microemulsions occurred at 30% wt/wt water. Cryo-FESEM photomicrographs revealed globular structures of microemulsions at higher than 15% wt/wt water. In addition, self-diffusion coefficients determined by NMR reflected that the diffusability of water increased at higher than 35% wt/wt water, while that of IPP was in reverse. Therefore, the results from all techniques are in good agreement and indicate that the water/oil and oil/water transition point occurred in the range of 30% to 35% wt/wt water.